Step-by-Step DHCP Failover Cluster on Windows Server 2012 R2


With Windows Server 2012, Microsoft has lastly launched the power to correctly cluster the DHCP server position. There are two totally different strategies of clustering obtainable: failover and cargo stability.

Failover clusters use the identical eighty/20 methodology as has all the time been used – the place one server owns at the least eighty% of a scope’s obtainable addresses and a second server personal the 20%. This allowed the second server to proceed registering new leases to shoppers if the first DHCP server went offline.

We nonetheless  comply with the eighty/20 rule, as there’s nonetheless a necessity to order a advisable 20% of a scope’s addresses for the recent standby. The important distinction now’s scope settings and choices replication between DHCP companion servers. We not have to re-create the scope and manually regulate choices on the second server.

Another profit is that the associate server can routinely take full possession of the scope, if the first servers is misplaced.

The failover DHCP cluster is outlined and configured on the scope degree. And in contrast to most different excessive-availability failover configurations out there on Windows Servers, it doesn’t use the Failover Clustering function.

This step-by-step tutorial will information you thru configuring a DHCP failover cluster on Windows Server 2012 R2.


  • An present Active Directory Domain.
  • Two Windows Server 2012 R2 servers which might be area members.

Install the DHCP Server Role

The DHCP server position have to be put in on each servers earlier than the cluster might be created.

  1. Log onto the primary server with an account that has administrative rights.
  2. Launch the Server Manager console.
  3. In the highest-proper nook, click on Manage.
  4. Click Add Roles and Features.
  5. On the Before You Begin web page, click on Next.
  6. On the Select set up sort display, guarantee Role-based mostly or function-based mostly set up is chosen, after which click on Next.
  7. On the Select vacation spot server display, guarantee Select a server from the server pool is chosen, choose the native server within the Server Pool listing, after which click on Next.
  8. On the Select server roles display, guarantee DHCP Server is checked. Click Add Feature when the Add Roles and Features Wizard dialog field pops-up.
  9. Click Next.
  10. On the Select options display, click on Next.
  11. On the DHCP Server display, click on Next.
  12. On the Confirmation display, click on Install.
  13. After the set up course of completes, there ought to be a hyperlink named Complete DHCP Configuration. Click it to start out the DHCP Server Active Directory authorization course of.
  14. On the Description display of the DHCP Post-Install Configuration wizard, click on Next.
  15. On the Authorization display of the DHCP Post-Install Configuration wizard, choose the suitable choice for choosing a consumer with Domain Admin rights. This is required to authorize the server. When finished, click on Commit.
  16. On the Summary display, assessment the output to make sure the authorization was profitable. Click Close.
  17. On the Results display of the Add Roles and Features Wizard, click on Close.
  18. Log onto the second server and repeat steps P via 17.

Create a DHCP Scope

The cluster can’t be created until a DHCP scope exists. Let’s create a easy scope to start out.

  1. Log onto the primary DHCP server.
  2. Launch the Server Manager console.
  3. On the highest-proper, click on Tools.
  4. Select DHCP from the Tools drop-down menu.
  5. From the DHCP tree on the left of the console, broaden the node named after the server.
  6. Select the IPv4 node by clicking it.
  7. Right-click on the IPv4 node after which choose New Scope.
  8. Go via the New Scope Wizard to create the brand new scope.

 Create the Failover Cluster

  1. From inside the DHCP console, proper-click on the IPv4 node of the DHCP server tree on the left-aspect.
  2. Click Configure Failover from the IPv4 context menu.
  3. When the Configure Failover dialog field seems, choose from the obtainable scopes that you want within the cluster. If you need to embrace all of them, examine the Select All field.
  4. Click Next.
  5. Click Add Server so as to add the DHCP companion server. Alternatively, you possibly can enter its IP handle or absolutely-certified area identify into the textual content area.
  6. Click Next.
  7. On the Create a brand new failover relationship display, give the cluster relationship a reputation. 

    Configure DHCP Failover Relationship

  8. Set the Maximum Client Lead Time worth utilizing hours and minutes.
  9. From the Mode drop-down menu, choose Hot Standby.
  10. From the Role of Partner Server drop-down, choose Standby. This makes the present server the lively cluster node and second server the passive node.
  11. Set how most of the scope addresses can be reserved for the standby server in percentages.
  12. In the Shared Secret textual content subject, enter a posh password that will probably be utilized by the servers. This ensures that solely servers who know the password can talk within the cluster.
  13. Click Next.
  14. Verify your settings, after which click on Finish.
  15. Log onto the second DHCP server.
  16. Launch the DHCP console and confirm that the scope we created on the primary DHCP server has been replicated to the second server.

Creating a DHCP Failover Cluster utilizing PowerShell

We can accomplish the identical process above utilizing PowerShell. This could be very helpful when administering the servers remotely from a shopper pc.

  1. Launch PowerShell.
  2. Use the Add-DhcpServerv4Failover cmdlet. The instance under creates a partnership (cluster) referred to as Toronto-Failover utilizing servers WS12-DHCP01 and WS12-DHCP02.
    Add-DhcpServerv4Failover -ComputerName ws12-dhcp01 -Name Toronto-Failover -PartnerServer ws12-dhcp02 -ServerRole Standby -ScopeId
  3. Verify the cluster’s configuration utilizing the Get-DhcpServerv4Failover cmdlet.
    Name                : SFO-SIN-Failover
    PartnerServer       :
    Mode                : HotStandby
    LoadBalancePercent  :
    ServerRole          : Standby
    ReservePercent      : H
    MaxClientLeadTime   : 01:00:00
    StateSwitchInterval :
    State               : Normal
    ScopeId             :
    AutoStateTransition : False
    EnableAuth          : False


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